26 CFR § 1.502-1 - Feeder organizations.
(a) In the case of an organization operated for the primary purpose of carrying on a trade or business for profit, exemption is not allowed under section 501 on the ground that all the profits of such organization are payable to one or more organizations exempt from taxation under section 501. In determining the primary purpose of an organization, all the circumstances must be considered, including the size and extent of the trade or business and the size and extent of those activities of such organization which are specified in the applicable paragraph of section 501.
(b) If a subsidiary organization of a tax-exempt organization would itself be exempt on the ground that its activities are an integral part of the exempt activities of the parent organization, its exemption will not be lost because, as a matter of accounting between the two organizations, the subsidiary derives a profit from its dealings with its parent organization, for example, a subsidiary organization which is operated for the sole purpose of furnishing electric power used by its parent organization, a tax-exempt educational organization, in carrying on its educational activities. However, the subsidiary organization is not exempt from tax if it is operated for the primary purpose of carrying on a trade or business which would be an unrelated trade or business (that is, unrelated to exempt activities) if regularly carried on by the parent organization. For example, if a subsidiary organization is operated primarily for the purpose of furnishing electric power to consumers other than its parent organization (and the parent's tax-exempt subsidiary organizations), it is not exempt since such business would be an unrelated trade or business if regularly carried on by the parent organization. Similarly, if the organization is owned by several unrelated exempt organizations, and is operated for the purpose of furnishing electric power to each of them, it is not exempt since such business would be an unrelated trade or business if regularly carried on by any one of the tax-exempt organizations. For purposes of this paragraph, organizations are related only if they consist of:
(1) A parent organization and one or more of its subsidiary organizations; or
(c) In certain cases an organization which carries on a trade or business for profit but is not operated for the primary purpose of carrying on such trade or business is subject to the tax imposed under section 511 on its unrelated business taxable income.
(d) Exception -
(1) Taxable years beginning before January 1, 1970. For purposes of section 502 and this section, for taxable years beginning before January 1, 1970, the term trade or business does not include the rental by an organization of its real property (including personal property leased with the real property).
(i) The deriving of rents described in section 512(b)(3)(A),
(3) Cross references and special rules.